1. Field of the Invention
The present invention generally relates to enhancement of blood or lymph flow in general, and to a portable pneumatic self-contained device for applying intermittent pressure on a body part in particular.
2. Discussion of the Related Art
Peripheral vascular disorders include venous, arterial or combined arteriovenous disorders. Venous thrombosis may seriously affect superficial or deep veins. Over time, serious conditions may develop to include edema, pain, stasis pigmentation, dermatitis, ulceration and the like. Serious cases of venous thrombosis may lead to phlegmasia cerulea dolens in which the extremities of the patient turns blue and may lead to gangrene and death. Various other ailments and conditions are likely to result from complications of venous thrombosis.
It is thought that most venous thrombosis occurrences begin in the valve cusps of deep calf veins. Tissue thromboplastin is released, forming thrombin and fibrin that trap RBCs and propagate proximally as a red or fibrin thrombus, which is the predominant morphologic venous lesion. Anticoagulant drugs such as heparin, the coumarin compounds, can prevent thrombosis from forming or extending. Antiplatelet drugs, despite intensive study, have not proved effective for prevention of venous thrombosis. Symptoms can appear within hours or sometimes longer. Other related venous conditions are varicose veins associated with valvular dysfunction causing aching, fatigue, and in some case subcutaneous induration and ulceration, superficial thrombophlebitis and even pulmonary embolism.
Arterial vascular disorders such as peripheral arterial occlusion may result in acute ischemia manifested in cold, painful and discolored extremities. In acute cases, the locations distal to the obstruction will be absent of pulse. Chronic occlusion will be manifested in the patient being able to walk to a lesser distance as the diseases progresses, causing unrelenting pain to the extremities, compromising tissue viability and leading to gangrene.
Increasing the flow of blood or lymph in the limb during periods of immobility is already a proven method to prevent the formation of DVT in the limb and to ease the suffering of peripheral vascular disorders. It secondarily prevents the formation of pulmonary embolism that commonly originates from such disorders. Increasing the venous return and arterial flow can also prevent formation of edema, pain and discomfort in the limb during periods of immobilization and assist in the prevention of arterial stenosis and occlusion.
Reduced circulation through a limb can also be observed in conditions affecting the arterial system such as in diabetes mellitus. It is believed that various vascular alterations such as accelerated atherosclerosis, where the arterial walls become thickened and loss their elasticity, diabetic microangiopathy, affecting capillaries, as well as neuropathy (loss and dysfunction of nerves) are responsible for the impaired circulation in the diabetic limb. The reduced blood supply to the limb entails stasis and ischemia in the distal limb. This ischemia leads to tissue death (necrosis) and secondary infections and inflammations. In addition, lack of cutaneus sensation caused by the loss of sensory nerves due to the diabetic neuropathy prevents the patient from being alert to the above-mentioned condition developing.
Enhancing circulation in general and prevention of stasis related disorders in particular, is achieved via non-portable large and cumbersome devices. Most of these devices can be used only by trained medical staff. Other methods of treatment suggest the use of worm compresses and medication.
Accordingly it is the object of the present invention to provide intermittent compression device for the enhancement of blood and lymph flow in a limb which is portable, self-contained and easily carried, small and lightweight, is easy to manufacture and is low cost. Such device will have enhanced energetic abilities enabling the efficient suction of blood and lymph though the arterial vessels. A further object of the invention is to provide such a device which provides intermittent compression using a fast and small pneumatic device, alternatively, combining the pneumatic and mechanical devices using low energy that does not involve tubing. It is a further object of the present invention to provide such a device which is simple to operate by a lay person without any special training in the field of medicine, is easily strapped over or attached to a limb and can be easily adjusted to fit persons of any size. Yet a further object of the invention is to provide such a device which allows for fast transitions from compressed to relaxed states and vice versa and which can exerts momentarily high forces by employing economic energy management.
Other advantages of the invention will be apparent from the description that follows.